noun [C] (mathematics数学) a series of numbers in which each is multiplied or divided by a fixed number to produce the next, for example 1, 3, 9, 27, 81 几何级数（每个数乘以或除以一个固定数所得出的一系列数字，如1、3、9、27、81） ☞Compare arithmetic progression. 与 arithmetic progression 比较。